Hybrid Accommodating Intraocular Lens Assemblages

ABSTRACT

Hybrid Accommodating Intra Ocular Lens (AIOL) assemblages including two discrete component parts in the form of a discrete base member for initial implantation in a vacated capsular bag and a discrete lens unit for subsequent implantation in the vacated capsular bag for anchoring to the discrete base member. The lens unit includes a lens optics having at least two lens haptics radially outwardly extending therefrom. The base member includes a flat circular base member centerpiece having zero optical power.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 16/302,266 filed on Nov. 16, 2018, which is a national-stageapplication under 35 USC 371 of international application No.PCT/IL2017/050566 filed on May 21, 2017, and claims priority under 35USC § 119 to the Israel patent application No. 245775 filed on May 22,2016, the entire disclosures of which are incorporated herein byreference in their entirety.

FIELD OF THE INVENTION

This invention relates to accommodating intraocular lens assemblages ingeneral and in-the-bag accommodating intraocular lens assemblages inparticular.

BACKGROUND OF THE INVENTION

Referring to FIG. 1 and FIG. 2, the structure and operation of a humaneye are described as context for the present invention. FIG. 1 and FIG.2 are cross section views of an anterior part of a human eye 10 having avisual axis VA for near vision and distance vision, respectively, in anaxial plane of the human body. The human eye 10 has an anteriortransparent cap like structure known as a cornea 11 connected at itscircumferential periphery to a spherical exterior body made of toughconnective tissue known as sclera 12 at an annular corneal limbus 13. Aniris 14 inwardly extends into the human eye 10 from its root 16 at thecorneal limbus 13 to divide the human eye's anterior part into ananterior chamber 17 and a posterior chamber 18. The iris 14 is a thinannular muscle structure with a central pupil. The iris 14 is activatedby inter alia ambient light conditions, focusing for near vision, andother factors for a consequential change in pupil diameter. An annularciliary body 19 is connected to zonular fibers 21 which in turn areperipherally connected to an equatorial edge of a capsular bag 22 havingan anterior capsule 23 and a posterior capsule 24 and containing anatural crystalline lens 26. Contraction of the ciliary body 19 allowsthe lens 26 to thicken to its natural thickness T1 along the visual axisVA for greater positive optical power for near vision (see FIG. 1).Relaxation of the ciliary body 19 tensions the zonular fibers 21 whichdraws the capsular bag 22 radially outward as shown by arrows A forcompressing the lens 26 to shorten its thickness along the visual axisVA to T2<T1 for lower positive optical power for distance vision (seeFIG. 2). Near vision is defined at a distance range of between about 33cm to 40 cm and requires an additional positive optical power of betweenabout 3 Diopter to 2.5 Diopter over best corrected distance vision.Healthy human eyes undergo pupillary miosis to about 2 mm pupil diameterfor near vision from an about 3 mm to 6 mm pupil diameter for distancevision corresponding to ambient illumination conditions.

Cataract surgery involves capsulorhexis in an anterior capsule 23 forenabling removal of a natural crystalline lens 26. Capsulorhexistypically involves preparing an about 4 mm to about 5 mm diametercircular aperture in an anterior capsule 23 to leave an annular anteriorcapsule flange 27 and an intact posterior capsule 24. FIG. 1 and FIG. 2denote the boundary of the circular aperture by arrows B. Separationbetween a capsular bag's annular anterior capsule flange 27 and itsintact posterior capsule 24 enables growth of capsular epithelial cellswhich naturally migrate over its internal capsule surfaces inducingopacification of a posterior capsule 24 abbreviated as PCO and/orcapsular fibrosis with capsular contraction. While secondary cataractsare ruptured by YAG laser to clear a visual axis and restore vision,capsular contraction is untreatable.

Accommodating Intraocular Lens (AIOL) assemblages designed to bepositioned within a vacated capsular bag 22 are known as in-the-bag AIOLassemblages. Presently envisaged in-the-bag AIOL assemblages are largemonolithic dual optics structures of inherent bulkiness that require alarge corneal incision for implantation in a human eye and properpositioning inside its capsular bag since a slight deviation of oneoptics of a dual optics structure from its visual axis results inoptical distortion. Moreover, previously envisaged in-the-bag AIOLassemblages do not lend to being formed with a toric lens component forcorrecting astigmatism since dialing a bulky dual optics structureinside a capsular bag to a predetermined angle required to correctastigmatism poses a great risk of tearing a capsular bag.

There is a need for improved in-the-bag AIOL assemblages.

SUMMARY OF THE INVENTION

The present invention is directed towards hybrid Accommodating IntraOcular Lens (AIOL) assemblages including two discrete component parts inthe form of a discrete base member for initial implantation in a vacatedcapsular bag and a discrete lens unit for subsequent implantation in thevacated capsular bag for anchoring thereto. The discrete lens unitincludes a lens optics having at least two lens haptics radiallyoutwardly extending therefrom. The discrete base member includes a flatcircular base member centerpiece. The lens optics and the base membercenterpiece are both made of suitable implantable bio-compatibletransparent optical grade material and necessarily have the samerefractive index. The lens optics and the base member centerpiece arepreferably made from the same material but can be made from differentmaterials.

The lens optics has an anterior lens optics surface for distance visioncorrection and a posterior lens optics surface having a central circlefor near vision correction. The posterior lens optics surface preferablyhas an annular multi-focal segment surrounding its central circlecalculated for affording good intermediate vision in an implantedhealthy eye. Alternatively, for implantation in an impaired vision eye,a degenerate lens unit can have a posterior lens optics surfaceconstituted by a mono-focal lens optics surface.

The base member centerpiece has a penetration property enabling aposterior lens optics surface to be intimately immerged in its anteriorbase member centerpiece surface when compressed thereagainst to create asingle refractive index optical continuum. Full ciliary body relaxationcauses a full immersion of the posterior lens optics surface in theanterior base member centerpiece surface thereby nullifying the opticalpowers of both the central circle and its surrounding annularmulti-focal segment such that only the anterior lens optics surface isoptically active for distance vision. Ciliary body contraction causes afull axial separation of the posterior lens optics surface from theanterior base member centerpiece surface such that both the anteriorlens optics surface and the posterior lens optics surface's centralcircle are optically active for near vision. In an intermediate ciliarybody state between ciliary body contraction and full ciliary bodyrelaxation, the posterior lens optics surface's central circle only isimmersed in the anterior base member centerpiece surface, and itsannular multi-focal segment is optically active together with theanterior lens optics surface for intermediate vision.

BRIEF DESCRIPTION OF DRAWINGS

In order to understand the invention and to see how it can be carriedout in practice, preferred embodiments will now be described, by way ofnon-limiting examples only, with reference to the accompanying drawingsin which similar parts are likewise numbered, and in which:

FIG. 1 is a cross section of an anterior part of a human eye in itsnatural near vision condition in an axial plane of the human body;

FIG. 2 is a cross section of an anterior part of a human eye in itsnatural distance vision condition in an axial plane of the human body;

FIG. 3 is a perspective front view of a hybrid AIOL assemblage includinga discrete lens unit and a discrete base member for in situ assembly ina capsular bag during cataract surgery;

FIG. 4 is a top plan view of the discrete lens unit;

FIG. 5 is a transverse cross section of the discrete lens unit alongline 5-5 in FIG. 4;

FIG. 6 is a top plan view of the discrete base member;

FIG. 7 is a transverse cross section of the discrete base member alongline 7-7 in FIG. 6;

FIG. 8 is a transverse cross section of an in-the-hand assembled hybridAIOL assemblage;

FIG. 9 is a transverse cross section of an edge of another discrete basemember;

FIG. 10 is a transverse cross section of an edge of yet another discretebase member;

FIG. 11 is a cross section of an implanted hybrid AIOL assemblage fornear vision corresponding to FIG. 1;

FIG. 12 is a cross section of the implanted hybrid AIOL assemblage fordistance vision corresponding to FIG. 2; and

FIG. 13 is a cross section of the implanted hybrid AIOL assemblage forintermediate vision.

DETAILED DESCRIPTION OF DRAWINGS

FIG. 3 show a hybrid AIOL assemblage 30 including a discrete lens unit40 and a discrete base member 60 for in situ assembly in a capsular bagduring cataract surgery. The discrete lens unit 40 includes a lensoptics 41 and at least two equispaced lens haptics 42 radially outwardextending from the lens optics 41. The discrete lens unit 40 preferablyincludes four equispaced lens haptics 42. The lens unit 40 can bemanufactured as a monolithic structure. Alternatively, the lens haptics42 can be manufactured separately from the lens optics 41 and attachedthereto using industry known attachment technologies. The discrete basemember 60 has a base member centerline 61 and includes a flat circularbase member centerpiece 62 and a base member surround 63. The basemember 60 can be manufactured as a monolithic structure. Alternatively,the base member surround 63 can be manufactured separately from the basemember centerpiece 62 and attached thereto using industry knownattachment technologies. The hybrid AIOL assemblage 30 is entirely madefrom implantable biocompatible material. The lens optics 41 and the basemember centerpiece 62 are made from optical grade transparent materialsand have the same refractive index. The lens optics 41 and the basemember centerpiece 62 are preferably formed from the same material.

FIG. 4 and FIG. 5 show the lens optics 41 has an optical axis 43 forco-axial alignment with a visual axis VA. The lens optics 41 has ananterior lens optics surface 44, a posterior lens optics surface 46 anda lens optics edge 47. The lens optics 41 has a similar diameter andthickness as standard IOLs currently being used for cataract surgery.The anterior lens optics surface 44 affords a primary optical powercalculated for optimal distance vision correction in an implanted eye.Healthy eyes require good vision at both near distance and intermediatedistances and therefore the posterior optic lens surface 46 preferablyhas a multifocal optical gradient from a maximal optical power at thelens optics axis 43 diminishing towards the lens optics edge 47.Accordingly, the posterior lens optics surface 46 includes a centercircle 48 having an approximate 2.5 mm diameter around the lens opticsaxis 43 corresponding to near vision pupil size under normal readingillumination conditions. The central circle 48 has the required addedpower to the principle distance correction optical power of the anteriorlens optics surface 44 for near vision in an intended implanted eye. Thecentral circle 48 typically has an optical power of around 3.0 Diopter.From the boundary of the central circle 48, the optical power isgradually decreased towards the lens optics edge 47 using manufacturingmethods known to the art. In a degenerate version of the discrete lensunit 40 for implantation in an impaired vision eye, the posterior lensoptics surface 46 can be constituted by a single mono-focal lens opticssurface for providing best correction for near vision only in anintended implanted eye.

Each lens haptics 42 has a lens haptics free end 51 with a lens hapticscurved edge 52 corresponding to a curvature of an anchoring interface ofthe discrete base member 60. Each lens haptics 42 preferably has amanipulation aperture 53 for enabling proper positioning of the lensunit 40 relative to the base member 60. Each lens haptics 42 preferablyhas an elongated anterior spacer pair 54 adjacent to the lens optics 41for spacing an anterior capsule flange 27 therefrom to enablecirculation of aqueous humor between an anterior capsule flange 27 andthe lens unit 40.

The anterior lens optics surface 44 but can also be designed forsimultaneous correction of astigmatism in an intended implanted eye.Accordingly, the lens unit 40 is provided with an optical axis marker 56for assisting correct alignment of the lens unit 40 with respect to ahuman visual axis VA during implantation. The optical axis marker 56 ispreferably placed on a lens haptics 42 not to impede vision. Themanipulation apertures 53 are employed for dialing a properly positionedlens unit 40 around the lens optics axis 43 for setting at a requiredposition for astigmatic correction.

FIG. 6 and FIG. 7 show the discrete base member 60 has a flat circularbase member centerpiece 62 having a flat circular anterior base membercenterpiece surface 64 and a flat circular posterior base membercenterpiece surface 66. The flat anterior and posterior base membercenterpiece surfaces 64 and 66 have zero optical power. The base membersurround 63 is formed with an elevated circumferential retainer 67 forforming a circumferential groove 68 with the anterior base membercenterpiece surface 64 for receiving the lens haptics free ends 51 foranchoring the discrete lens unit 40 on the discrete base member 60. Thebase member surround 63 preferably has a square cross section forpreventing the migration of epithelial cells from a capsular periphery.FIG. 8 shows the assembled hybrid AIOL assemblage 30 on mounting thelens unit 40 on the base member 60 by means of the lens haptics freeends 51 being flexed into the circumferential groove 68 such that thelens haptics 42 urge the posterior lens optics surface 46 away from theanterior base member centerpiece surface 64.

Capsular bag size can vary by several millimeters. The hybrid AIOLassemblages 30 are designed such that the same discrete lens unit 40 canbe implanted in different sized human capsular bags. This is achieved bythe provision of discrete base members 60 having their circumferentialgroove 68 at the same radius R relative to the base member centerline 61and compensating for capsular size differences by radial outwardextending of the base member surround 63 and the elevatedcircumferential retainer 67 as can be seen on comparison of FIG. 9 toFIG. 7. FIG. 10 shows an alternative elevated circumferential retainer67 in the form of a pliable rim 69 designed to be flexed towards theanterior base member centerpiece surface 64 by the anterior capsuleflange 27 as denoted by arrow C to improve the mechanical interfacebetween the anterior capsule flange 27 and the lens haptics 42. Thepliable rim 69 is deployed at the same radius R from the base membercenterline 61 and capsular size differences are compensated by radialoutward extending of the base member surround 63 with respect to thebase member centerline 61.

FIG. 11 show an implanted hybrid AIOL assemblage 30 in an operative nearvision state corresponding to FIG. 1. Full ciliary body contraction isaccompanied by iris contraction to about 2.5 mm diameter pupil size.FIG. 11 shows the anterior capsule flange 27 contacting the anteriorlens optics surface 44 and/or the haptics spacers 54 but not urging thelens optics 41 towards the base member centerpiece 62 such that theposterior lens optics surface 46 is spaced apart from the anterior basemember centerpiece surface 64. Accordingly, the hybrid AIOL assemblage30 affords the combined optical power of the anterior lens opticssurface 44 and the central circle 48's optical power to enable nearvision.

FIG. 12 shows the implanted hybrid AIOL assemblage 30 in an operativedistance vision state corresponding to FIG. 2. FIG. 12 shows theanterior capsule flange 27 pressing down on the anterior lens opticssurface 44 and/or the haptics spacers 54 for urging the lens optics 41towards the base member centerpiece 62. The posterior lens opticssurface 46 is entirely intimately immerged in the anterior base membercenterpiece surface 64 such that the posterior lens optics surface 46and the anterior base member centerpiece surface 64 create a singlerefractive index optical continuum of zero optical power whereby thehybrid AIOL assemblage 30 affords optical power by virtue of theanterior lens optics surface 44 suitably determined for best distancevision of an intended implanted eye.

FIG. 13 shows the implanted hybrid AIOL assemblage 30 in an operativeintermediate vision state. The intermediate vision involves a ciliarybody contraction much smaller than for near vision leading to theposterior lens optics surface 46 being partially intimately immerged inthe anterior base member centerline surface 64. As shown, only thecentral circle 48 and the anterior base member centerpiece surface 64create a single refractive index optical continuum of zero opticalpower. The annular multi-focal segment 49 is spaced apart from theanterior base member centerpiece surface 64 thereby affording therequired additional optical power for intermediate vision.

While the invention has been described with respect to a limited numberof embodiments, it will be appreciated that many variations,modifications, and other applications of the invention can be madewithin the scope of the appended claims.

1. A discrete lens unit for use in a hybrid accommodating intraocularlens assemblage for implantation in a post-capsulorhexis human eyehaving a visual axis, an annular ciliary body, and a vacated capsularbag having an annular anterior capsule flange and an intact posteriorcapsule, the ciliary body having a relaxed ciliary body state fordistance vision and a contracted ciliary body state for near vision, theciliary body peripherally tensioning the capsular bag on its relaxationfrom its contracted ciliary body state to its relaxed ciliary bodystate, wherein the hybrid accommodating intraocular lens assemblagecomprises: (a) a discrete base member having a base member centerlineand including a flat circular base member centerpiece and a peripheralbase member surround, said flat circular base member centerpiece havinga base member centerpiece refractive index, an anterior base membercenterpiece surface and a posterior base member centerpiece surface,said discrete base member having an elevated circumferential retainerbounding a circumferential groove with said anterior base membercenterpiece surface; and (b) said discrete lens unit comprising: i) alens optic having a lens optic refractive index, a lens optic axis forco-axial alignment with the visual axis, an anterior lens optic surfacewith a primary optical power for distance vision and a posterior lensoptic surface having a central circle with an additional optical powerto said primary optical power for near vision; and ii) at least twospaced apart resiliently flexible lens haptics radially extending fromsaid lens optic for insertion in said circumferential groove foranchoring said discrete lens unit on said discrete base member forurging said lens optic away from said discrete base member forseparating said posterior lens optic surface from said anterior basemember centerpiece surface, said at least two spaced apart resilientlyflexible lens haptics each having a free end remote from said lensoptic, said elevated circumferential retainer being configured tooverlie said free ends for anchoring said discrete lens optic on saiddiscrete base member, and enabling rotation of said discrete lens unitto a predetermined position relative to said discrete base memberstationary in the post-capsulorhexis human eye, and wherein said basemember centerpiece and said lens optic have the same refractive index,and whereupon, pursuant to an initial implantation of said discrete basemember in the vacated capsular bag and a subsequent implantation of saiddiscrete lens unit in the vacated capsular bag between said base memberand the anterior capsule flange, in the relaxed ciliary body state, thevacated capsular bag urges said lens optic and said base member towardseach other such that said posterior lens optic surface is intimatelyimmerged in said anterior base member centerpiece surface for creating asingle refractive index optical continuum nullifying said posterior lensoptic surface's optical power whereby the hybrid accommodatingintraocular lens assemblage has optical power for distance vision only,and in the contracted ciliary body state, the vacated capsular bagenables said at least two spaced apart resiliently flexible lens hapticsto space apart said lens optic and said base member such that saidposterior lens optic surface is spaced apart from said anterior basemember centerpiece surface for adding said central circle's additionaloptical power to said anterior lens optic surface's primary opticalpower whereby the hybrid accommodating intraocular lens assemblage has acombined optical power for near vision.
 2. The discrete lens unitaccording to claim 1, wherein said posterior lens optic surface includesan annular multi-focal segment surrounding said central circle with agradual decreasing optical power from said lens optic axis towards saidat least two spaced apart resiliently flexible lens haptics forintermediate vision correction, whereupon, in an intermediate ciliarybody state between the relaxed ciliary body state and the contractedciliary body state, said central circle is intimately immerged in saidanterior base member centerpiece surface for creating a singlerefractive index optical continuum nullifying said central circle'soptical power and said annular multi-focal segment is spaced apart fromsaid anterior base member centerpiece surface for intermediate vision.3. The discrete lens unit according to claim 1, wherein said posteriorlens optic surface is a mono-focal lens optic surface from said lensoptic axis to said at least two spaced apart resiliently flexible lenshaptics.
 4. The discrete lens unit according to claim 1, wherein eachlens haptics of said at least two lens haptics includes at least oneanterior spacer for spacing the anterior capsule flange therefrom onsaid subsequent implantation of said discrete lens unit in the vacatedcapsular bag.
 5. The discrete lens unit according to claim 1, whereinsaid anterior lens optic surface is combined with a toric optical designfor correction of astigmatism, and said discrete lens unit includes anoptical axis marker for assisting alignment of said discrete lens unitrelative to a visual axis during implantation of said discrete lensunit.
 6. A discrete base member for use in a hybrid accommodatingintraocular lens assemblage for implantation in a post-capsulorhexishuman eye having a visual axis, an annular ciliary body, and a vacatedcapsular bag having an annular anterior capsule flange and an intactposterior capsule, the ciliary body having a relaxed ciliary body statefor distance vision and a contracted ciliary body state for near vision,the ciliary body peripherally tensioning the capsular bag on itsrelaxation from its contracted ciliary body state to its relaxed ciliarybody state, wherein the hybrid accommodating intraocular lens assemblagecomprises: (a) said discrete base member having a base member centerlineand including a flat circular base member centerpiece and a peripheralbase member surround, said flat circular base member centerpiece havinga base member centerpiece refractive index, an anterior base membercenterpiece surface and a posterior base member centerpiece surface,said base member having an elevated circumferential retainer bounding acircumferential groove with said anterior base member centerpiecesurface; and (b) a discrete lens unit comprising: i) a lens optic havinga lens optic refractive index, a lens optic axis for co-axial alignmentwith the visual axis, an anterior lens optic surface with a primaryoptical power for distance vision and a posterior lens optic surfacehaving a central circle with an additional optical power to said primaryoptical power for near vision; and ii) at least two spaced apartresiliently flexible lens haptics radially extending from said lensoptic for insertion in said circumferential groove for anchoring saiddiscrete lens unit on said discrete base member for urging said lensoptic away from said discrete base member for separating said posteriorlens optic surface from said anterior base member centerpiece surface,said at least two spaced apart resiliently flexible lens haptics eachhaving a free end remote from said lens optic, said elevatedcircumferential retainer being configured to overlie said free ends foranchoring said discrete lens optic on said discrete base member, andenabling rotation of said discrete lens unit to a predetermined positionrelative to said discrete base member stationary in thepost-capsulorhexis human eye, and wherein said base member centerpieceand said lens optic have the same refractive index, and whereupon,pursuant to an initial implantation of said discrete base member in thevacated capsular bag and a subsequent implantation of said discrete lensunit in the vacated capsular bag between said base member and theanterior capsule flange, in the relaxed ciliary body state, the vacatedcapsular bag urges said lens optic and said base member towards eachother such that said posterior lens optic surface is intimately immergedin said anterior base member centerpiece surface for creating a singlerefractive index optical continuum nullifying said posterior lens opticsurface's optical power whereby the hybrid accommodating intraocularlens assemblage has optical power for distance vision only, and in thecontracted ciliary body state, the vacated capsular bag enables said atleast two spaced apart resiliently flexible lens haptics to space apartsaid lens optic and said base member such that said posterior lens opticsurface is spaced apart from said anterior base member centerpiecesurface for adding said central circle's additional optical power tosaid anterior lens optic surface's primary optical power whereby thehybrid accommodating intraocular lens assemblage has a combined opticalpower for near vision.
 7. The discrete base member according to claim 6,wherein said peripheral base member surround has a square cross sectionin a transverse cross section.
 8. The discrete base member according toclaim 6, wherein said elevated circumferential retainer is constitutedby a pliable rim.